Association of overexpression of TIF1γ with colorectal carcinogenesis and advanced colorectal adenocarcinoma

Sequence Alignment between TRIM33 Gene and Human Noncoding RNAs: A Potential Explanation for Paraneoplastic Dermatomyositis

BACKGROUND

This computational analysis investigated sequence complementarities between the TRIM33 gene and human noncoding (nc)RNAs and characterized their interactions in the context of paraneoplastic dermatomyositis.

METHODS

TRIM33 FASTA sequence (NCBI Reference Sequence: NC_000001.11) was used for BLASTN analysis against Human GRCh38 in the Ensembl.org database. Retrieved ncRNAs showing hits to TRIM33 were searched in the GeneCards.org database and further analyzed through RNAInter, QmRLFS-finder, Spliceator, and NcPath enrichment analysis.

RESULTS

A total of 100 hits were found, involving the lncRNAs NNT-AS1, MKLN1-AS, LINC01206, and PAXBP1-AS1, whose dysregulation has been reported in either cancer or dermatomyositis. Additionally, the lncRNAs NNT-AS1 and PAXBP1-AS1 may interact with microRNA-142-3p, reducing its expression and increasing that of TRIM33. Sequence complementarity affected only TRIM33 intron 1, possibly resulting in alternatively spliced isoforms of TIF1γ with increased immunogenicity. The results also revealed nucleotide alignment between TRIM33 and the gene regulatory elements of 28 ncRNA genes involved in immune pathways.

CONCLUSIONS

This pivotal study demonstrates sequence complementarity between TRIM33 and human ncRNAs dysregulated in cancer and dermatomyositis. This scenario may lead to the overproduction of more immunogenic TIF1γ variants in tumors and the stimulation of autoimmunity. Further experimental analyses using targeted methods such as Western blot or Chip-Seq are required to confirm these data.

TIF1γ and SMAD4 regulation in colorectal cancer: impact on cell proliferation and liver metastasis

We investigated the effects of transcriptional intermediary factor 1γ (TIF1γ) and SMAD4 on the proliferation and liver metastasis of colorectal cancer (CRC) cells through knockdown of TIF1γ and/or SMAD4 and knockdown of TIF1γ and/or restoration of SMAD4 expression. Furthermore, we examined TIF1γ and SMAD4 expression in human primary CRC and corresponding liver metastatic CRC specimens. TIF1γ promoted but SMAD4 inhibited the proliferation of CRC cells by competitively binding to activated SMAD2/SMAD3 complexes and then reversely regulating c-Myc, p21, p27, and cyclinA2 levels. Surprisingly, both TIF1γ and SMAD4 reduced the liver metastasis of all studied CRC cell lines via inhibition of MEK/ERK pathway-mediated COX-2, Nm23, uPA, and MMP9 expression. In patients with advanced CRC, reduced TIF1γ or SMAD4 expression was correlated with increased invasion and liver metastasis and was a significant, independent risk factor for recurrence and survival after radical resection. Patients with advanced CRC with reduced TIF1γ or SAMD4 expression had higher recurrence rates and shorter overall survival. TIF1γ and SMAD4 competitively exert contrasting effects on cell proliferation but act complementarily to suppress the liver metastasis of CRC via MEK/ERK pathway inhibition. Thus, reduced TIF1γ or SMAD4 expression in advanced CRC predicts earlier liver metastasis and poor prognosis.

TRIM33 Is a Co-Regulator of Estrogen Receptor Alpha

Estrogen receptor alpha (ER)-positive breast cancer is responsible for over 60% of breast cancer cases in the U.S. Among patients diagnosed with early-stage ER+ disease, 1/3 will experience recurrence despite treatment with adjuvant endocrine therapy. ER is a nuclear hormone receptor responsible for estrogen-driven tumor growth. ER transcriptional activity is modulated by interactions with coregulators. Dysregulation of the levels of these coregulators is involved in the development of endocrine resistance. To identify ER interactors that modulate transcriptional activity in breast cancer, we utilized biotin ligase proximity profiling of ER interactomes. Mass spectrometry analysis revealed tripartite motif containing 33 (TRIM33) as an estrogen-dependent interactor of ER. shRNA knockdown showed that TRIM33 promoted ER transcriptional activity and estrogen-induced cell growth. Despite its known role as an E3 ubiquitin ligase, TRIM33 increased the stability of endogenous ER in breast cancer cells. TRIM33 offers a novel target for inhibiting estrogen-induced cancer cell growth, particularly in cases of endocrine resistance driven by ER (ESR1) gene amplification or overexpression.

Characteristics of anti-transcriptional intermediary factor 1 gamma autoantibody-positive dermatomyositis patients in Singapore

Introduction: This study aimed to determine the clinical profile and outcome of anti-transcriptional intermediary factor 1 gamma autoantibody (anti-TIF1-γ Ab)-positive dermatomyositis patients and propose cancer screening programmes based on regional cancer trends. Method: Data on history, physical findings and investigations were collected using chart review on dermatomyositis patients seen at a tertiary hospital in Singapore from 1 January 2015 to 30 June 2021. Comparisons were made between anti-TIF1-γ Ab-positive and anti-TIF1-γ Ab-negative dermatomyositis. Results: Ninety-six dermatomyositis patients were analysed and 36 patients were positive for anti-TIF1-γ Ab. Anti-TIF1-γ Ab-positive patients had more frequent heliotrope rashes, shawl sign, periungual erythema, holster sign, Gottron’s papules, dysphagia and truncal weakness (P<0.05). They had less frequent interstitial lung disease, polyarthritis, cutaneous ulcers, palmar papules and mechanic’s hands (P<0.05). After 48 months of follow-up, a higher proportion of anti-TIF1-γ Ab-positive patients developed cancer compared with Ab-negative patients (63.9% versus 8.5%; odds ratio 19.1, 95% confidence interval 6.1–59.8; P<0.001). Nasopharyngeal carcinoma (NPC) and breast cancer were the most common malignancies, followed by bowel, lung and non-Hodgkin lymphoma. Most malignancies (78.3%) occurred within 13 months prior to, or 4 months after the onset of dermatomyositis. The mortality rate for anti-TIF1-γ Ab-positive patients was significantly higher than Ab-negative patients (36.1% vs 16.7%, P=0.031), and Kaplan-Meier survival estimates at 24 months were 66% and 89%, respectively (P=0.0153). Conclusion: These observational data support periodic screening of NPC and other malignancies in patients with anti-TIF1-γ Ab-positive dermatomyositis in Singapore. Keywords: Autoantibody, cancer, dermatomyositis, nasopharyngeal carcinoma, transcriptional intermediary factor 1 gamma

The use and diagnostic value of testing myositis-specific and myositis-associated autoantibodies by line immuno-assay: a retrospective study

AIMS

Line immune-assays (LIA) for the detection of myositis-specific antibodies (MSA) are used widely for characterization of idiopathic inflammatory myopathies (IIM). Their current use and significance for the diagnosis of IIM remains unclear.

METHODS

In this retrospective analysis, we retrieved clinical diagnoses of patients tested for MSA and myositis-associated antibodies (MAA) Jo-1, Mi-2α, Mi-2β, TIF1γ, SRP, MDA-5, NXP-2, SAE, PL-7, PL-12, EJ, OJ, PM-Scl100, PM-Scl75 and Ku. We calculated clinical specificity, clinical sensitivity, negative- and positive predictive values (PPV) as well as positive and negative likelihood ratios.

RESULTS

In total, we analyzed 3167 samples. After exclusion of repeated measurements and patients with insufficient clinical information, data of 1118 patients were available for analysis. A total of 242 patients tested positive for at least one antibody, of which 45 patients had a diagnosis of IIM; 25 IIM patients were negative for all MSA/MAA. Clinical specificity of MSA/MAA for the diagnosis of IIM ranged between 94.2% and 99.9%. Clinical sensitivity and PPV across all antibodies tested ranged from 0.0% to 12.9% and 0.0% to 72.7%, respectively.

CONCLUSION

In clinical practice MSA/MAA are used widely for diagnostic work-up of IIM, resulting in a low pre-test probability. Clinicians should be aware that PPVs for most MSA/MAA are low.

Clinical features of anti-transcription intermediary factor 1γ (TIF1γ)-positive dermatomyositis with internal malignancy and investigation of the involvement of TIF1γ expression in tumors in the pathogenesis of cancer-associated dermatomyositis

Anti-transcription intermediary factor 1γ (anti-TIF1γ) antibody (Ab) is significantly associated with internal malignancies in adult patients with dermatomyositis (DM). Although pathogenesis of cancer-associated DM is unknown, TIF1γ overexpression in tumors has been considered to be critical for the development of DM. The objective of this study was to investigate clinical characteristics of patients with anti-TIF1γ Ab-positive DM and elucidate risk factors that are potentially associated with internal malignancy. In addition, we compared the expression of TIF1γ in tumor tissues of patients with anti-TIF1γ Ab-positive DM, anti-TIF1γ Ab-negative DM and without DM in order to investigate the pathogenesis of cancer-associated DM. We analyzed 77 Japanese patients with DM, and found 19 patients to be positive for anti-TIF1γ Ab. Patients with anti-TIF1γ Ab-positive DM were older and presented heliotrope rash and flagellate erythema more frequently than patients without anti-TIF1γ Ab (P < 0.05). Interstitial lung disease (ILD) and rapidly progressive ILD, as well as palmar violaceous erythema, were less frequent in patients with anti-TIF1γ Ab than in patients without. Furthermore, internal malignancy and dysphagia were significantly more frequent in the anti-TIF1γ Ab-positive group (P < 0.01). Male sex and dysphagia were significantly associated with internal malignancy in patients with anti-TIF1γ Ab-positive DM (P < 0.01 and <0.05, respectively). Using immunohistochemistry, we examined the TIF1γ expression in tumors of 11 patients with cancer-associated DM (anti-TIF1γ Ab-positive, nine; anti-TIF1γ Ab-negative, two) and 25 patients without DM. TIF1γ was highly expressed in all tumors, and there was no significant difference in TIF1γ expression between patients with and without DM. Furthermore, TIF1γ expressions in tumors were similar irrespective of the presence of anti-TIF1γ Ab. These results suggest that anti-TIF1γ antibody may not be simply induced by overexpression of TIF1γ in tumors in patients with DM, but that other mechanisms may exist.

TIF1 Proteins in Genome Stability and Cancer

Genomic instability is a hallmark of cancer cells which results in excessive DNA damage. To counteract this, cells have evolved a tightly regulated DNA damage response (DDR) to rapidly sense DNA damage and promote its repair whilst halting cell cycle progression. The DDR functions predominantly within the context of chromatin and requires the action of chromatin-binding proteins to coordinate the appropriate response. TRIM24, TRIM28, TRIM33 and TRIM66 make up the transcriptional intermediary factor 1 (TIF1) family of chromatin-binding proteins, a subfamily of the large tripartite motif (TRIM) family of E3 ligases. All four TIF1 proteins are aberrantly expressed across numerous cancer types, and increasing evidence suggests that TIF1 family members can function to maintain genome stability by mediating chromatin-based responses to DNA damage. This review provides an overview of the TIF1 family in cancer, focusing on their roles in DNA repair, chromatin regulation and cell cycle regulation.

Anti-TIF1-γ autoantibodies: warning lights of a tumour autoantigen

Anti-transcription intermediary factor 1 (TIF1)-γ autoantibodies are robustly linked with cancer-associated DM in adults. This review aims to give an overview of the physiological context of TIF1-γ and to determine whether there is a pathophysiological link between anti-TIF1-γ autoantibodies and the occurrence of cancer. Detection of anti-TIF1-γ autoantibodies has a high sensitivity and specificity for cancer-associated DM in adults and is therefore useful for both diagnosis and cancer risk stratification. The function of the autoantigen, TIF1-γ, may provide insight into the mechanism behind this association. TIF1-γ is a ubiquitously present protein involved in various biological pathways, including TGF-β signalling. In cancer, it can act either as a tumour suppressor or promoter, depending on the cellular context and cancer stage. Evolving data provide pathophysiological insights, linking anti-TIF1-γ autoantibodies to both the anti-tumour response and to muscle and skin damage. TIF1-γ expression is increased in muscle and skin tissue of patients with DM. Mutations or loss-of-heterozygosity in TIF1-γ alleles in malignant tissue may result in the expression of tumour-specific neo-antigens stimulating autoantibody production. The newly formed autoantibodies are hypothesized to cross-react with antigens in muscle and skin, driving the development of DM. Based on the current evidence, anti-TIF1-γ autoantibodies should be considered warning lights of a potential tumour autoantigen and should alert the physician to the possibility of an underlying cancer.

A Case of Dermatomyositis Along with Esophageal Cancer and Screening of Serum Transcriptional Intermediary Factor 1 Gamma Antibodies in Various Cancer Patients

Patient: Male, 70-year-old

Final Diagnosis: Esophageal cancer

Symptoms: Muscle pain • weaknes of lower limbs

Medication: —

Clinical Procedure: Biopsy of the skin

Specialty: Rheumatology

Analysis of myositis autoantibodies in Chinese patients with cancer-associated myositis

Background

Cancer‐associated myositis (CAM) has poor prognosis and causes higher mortality. In general, myositis‐specific autoantibodies (MSAs) and myositis‐associated autoantibodies (MAAs) have been shown to be useful biomarkers for its diagnosis.

Methods

In the present study, focus was given in assessing the presence, prevalence, and diagnostic values of myositis autoantibodies in Chinese patients diagnosed with CAM. The sera collected from 49 CAM patients, 108 dermatomyositis/polymyositis (DM/PM) patients without cancer, 105 disease controls, and 60 healthy controls were detected for the presence of 16 autoantigens (Jo‐1, OJ, EJ, PL‐7, PL‐12, MDA5, TIF1γ, Mi‐2α, Mi‐2β, SAE1, NXP2, SRP, Ku, PM‐Scl75, PM‐Scl100, and Ro‐52) using a commercial Euroline assay.

Results

The frequency of anti‐TIF1γ was significantly higher in CAM patients than in DM/PM patients without cancer (46.9% vs 14.8%, P < .001). Importantly, the sensitivity and specificity for this MSA were 46.9% and 85.2%, respectively. These helped to differentiate CAM patients from DM/PM patients without cancer. However, there was no difference in other MSAs and MAAs between CAM and DM/PM patients without cancer.

Conclusion

The present study indicates that anti‐TIF1γ levels can serve as important biomarkers for CAM diagnosis and help in distinguishing between CAM and DM/PM patients without cancer.

The Tripartite Nexus: Autophagy, Cancer, and Tripartite Motif-Containing Protein Family Members

Autophagy is a cellular degradative process that has multiple important actions in cancer. Autophagy modulation is under consideration as a promising new approach to cancer therapy. However, complete autophagy dysregulation is likely to have substantial undesirable side effects. Thus, more targeted approaches to autophagy modulation may prove clinically beneficial. One potential avenue to achieving this goal is to focus on the actions of tripartite motif-containing protein family members (TRIMs). TRIMs have key roles in an array of cellular processes, and their dysregulation has been extensively linked to cancer risk and prognosis. As detailed here, emerging data shows that TRIMs can play important yet context-dependent roles in controlling autophagy and in the selective targeting of autophagic substrates. This review covers how the autophagy-related actions of TRIM proteins contribute to cancer and the possibility of targeting TRIM-directed autophagy in cancer therapy.

Inhibition of Endoglin Exerts Antitumor Effects through the Regulation of Non-Smad TGF-β Signaling in Angiosarcoma

Angiosarcoma is a rare malignant tumor derived from endothelial cells, and its prognosis is poor because advanced angiosarcoma is often resistant to taxane therapy. Endoglin (CD105) acts as a coreceptor for TGF-β signaling and is overexpressed in tumor-associated endothelial cells and enhances tumor angiogenesis. Numerous clinical trials are testing the effectiveness of anti-endoglin antibodies in various types of malignancies. Here, we investigated the role of endoglin in the pathogenesis of angiosarcoma and whether endoglin inhibition results in antitumor activity. Endoglin was overexpressed in angiosarcoma, and its inhibition was effective in promoting apoptosis and the suppression of migration, invasion, tube formation, and Warburg effect in angiosarcoma cells. Knockdown of endoglin activated caspase 3/7 that is essential for apoptosis, reduced survivin levels, and decreased paxillin and vascular endothelial cadherin phosphorylation and matrix metalloproteinase 2 and matrix metalloproteinase 9 activities in angiosarcoma cells. Although endoglin is a coreceptor that regulates TGF-β signaling, the antitumor effect of endoglin in angiosarcoma was not based on Smad signaling regulation but on non-Smad TGF-β signaling. Taken together, these results indicated that endoglin could be a novel therapeutic target for angiosarcoma.

The Combination of IgA and IgG autoantibodies against Transcriptional Intermediary Factor-1γ contributes to the early diagnosis of Lung Cancer

Objective: The aberrant expression of tumor-associated antigens (TAAs) is responsible for the release of large amounts of autoantibodies in sera, and serum autoantibody detection has been demonstrated to contribute to the early diagnosis of malignancies. Recent studies showed the closely correlation of transcriptional intermediary factor-1γ (TIF1γ) with some malignancies. In our pilot study, we found aberrantly high expression of TIF1γ protein existed in cancer tissues other than matched paracancerous tissues of patients with lung cancer (LC) at early stage by immunohistochemistry (IHC) staining. As a result, this study aims to detect the expression of autoantibodies against TIF1γ in sera of patients with LC at early stage by using enzyme-linked immunosorbent assay (ELISA) and investigate its potential value for the early diagnosis of LC. Methods: The expressions of TIF1γ protein in 60 pairs of LC tissues and matched paracancerous tissues were detected by IHC staining. The levels of anti-TIF1γ-IgA, IgG, IgM, and IgE in the sera of 248 patients with LC at early stage, 200 patients with lung benign lesions (LBL), and 218 healthy controls (HC) were detected by ELISA, respectively. Western blot was used to validate the ELISA results of serum autoantibodies against TIF1γ. Results: The positive rate of TIF1γ protein expression in LC tissues was 83.33%, which was significantly higher than 25.00% in paracancerous tissues (P<0.01). The levels and positive rates of serum anti-TIF1γ-IgM and anti-TIF1γ-IgE in early LC group had no significant difference from that in LBL group and HC group (P>0.05), while the levels and positive rates of anti-TIF1γ-IgA and anti-TIF1γ-IgG were significantly higher than that in LBL group and HC group (P<0.01), of which anti-TIF1γ-IgA showed the area under the receiver operating characteristic curve (AUC) of 0.704 for the patients with LC at early stage, with 28.20% sensitivity at 95.93% specificity, and anti-TIF1γ-IgG showed the AUC of 0.622 for the patients with LC at early stage, with 18.54% sensitivity at 94.25% specificity. The results of anti-TIF1γ-IgA and anti-TIF1γ-IgG in western blot were consistent with that in ELISA. Additionally, the combination of anti-TIF1γ-IgA and anti-TIF1γ-IgG improved the AUC to 0.734, with 38.31% sensitivity at 92.34% specificity. Conclusions: There is a strong humoral immune response to autologous TIF1γ existing in patients with early LC. Both serum anti-TIF1γ-IgA and anti-TIF1γ-IgG show the diagnostic value for the patients with LC at early stage, of which anti-TIF1γ-IgA is donstrated to be a preferable biomarker, and the combined detection of anti-TIF1γ-IgA and anti-TIF1γ-IgG might contribute to the further improvement of early diagnosis for LC.

Colorectal Cancer Among Gout Patients Undergoing Colonoscopy

BACKGROUND/OBJECTIVE

The connection between gout and various cancers remains unclear. We assessed the relationship between gout and colorectal cancer in a population of veterans.

METHODS

We reviewed the Computerized Patient Record System of the VA New York Harbor Health Care System to assess the 10-year occurrence of colorectal cancer in patients with gout undergoing colonoscopy, versus patients with osteoarthritis but no gout.

RESULTS

Gout and osteoarthritis subjects were similar in age, ethnicity, body mass index, and smoking history. Among 581 gout and 598 osteoarthritis subjects with documented colonoscopies, the 10-year prevalence of colorectal cancer was significantly lower in gout (0.8%) versus osteoarthritis (3.7%) (p = 0.0008) patients. Differences in colorectal cancer rates remained significant after stratifying for nonsteroidal anti-inflammatory drug use. Among gout subjects, use of colchicine and/or allopurinol, as well as the presence/absence of concomitant osteoarthritis, did not influence colorectal cancer occurrence. On subanalysis, differences in colorectal cancer occurrence between gout and osteoarthritis subjects persisted among those who underwent diagnostic (0.5% in gout vs 4.6% in osteoarthritis subjects, p < 0.001) but not screening (0.9% in gout subjects vs 1% in osteoarthritis subjects, p = 1.0) colonoscopy. There was no significant difference in nonmalignant colorectal polyp occurrence between gout and osteoarthritis subjects.

CONCLUSIONS

Subjects with gout had decreased colonoscopy-documented occurrence of colorectal cancer compared with osteoarthritis subjects, suggesting a possible protective effect.

The Roles of TIF1γ in Cancer

Transcriptional intermediary factor 1 γ (TIF1γ), also known as TRIM33, RFG7, PTC7, or Ectodermin, is an E3 ubiquitin-ligase family member with a ring-box-coiled-coil region. It can regulate TGF-β/Smad signaling in two different ways in different cellular contexts. On one hand, TIF1γ can monoubiquitinate Smad4 to inhibit the formation of Smad2/3/4 nuclear complexes. On the other hand, TIF1γ can function as a cofactor of phosphorylated (p)-Smad2/3, competing with Smad4 to inhibit the formation of the Smad2/3/4 complex. In addition, TIF1γ has been reported to play a role in transcription elongation, cellular differentiation, embryonic development, and mitosis. As transforming growth factor-β (TGF-β) superfamily signaling plays an important role in the occurrence and development of cancer, and TIF1γ was reported to be involved in the regulation of TGF-β superfamily signaling, studies on TIF1γ during the last decade have focused on its role in the development of cancer. However, TIF1γ can function either as a tumor suppressor or promoter in different cellular contexts, yet there are few reviews focusing on the roles of TIF1γ in cancer. Hence, in this paper we systematically review and discuss the roles of TIF1γ in cancer. Firstly, we review the biological features, the regulatory mechanisms and the related signaling pathways of TIF1γ. Next, we illustrate the roles of TIF1γ in different tumors. We then provide a tentative hypothesis that explains the dual roles of TIF1 γ in cancer. Finally, we provide our viewpoint regarding the future developments of cancer research focusing on TIF1γ, especially in relation to the effects of TIF1γ on tumoral immunity.

Clinicopathological Characterization and Prognostic Implication of SMAD4 Expression in Colorectal Carcinoma

Background

SMAD family member 4 (SMAD4) has gained attention as a promising prognostic factor of colorectal cancer (CRC) as well as a key molecule to understand the tumorigenesis and progression of CRC.

Methods

We retrospectively analyzed 1,281 CRC cases immunohistochemically for their expression status of SMAD4, and correlated this status with clinicopathologic and molecular features of CRCs.

Results

A loss of nuclear SMAD4 was significantly associated with frequent lymphovascular and perineural invasion, tumor budding, fewer tumor-infiltrating lymphocytes, higher pT and pN category, and frequent distant metastasis. In contrast, tumors overexpressing SMAD4 showed a significant association with sporadic microsatellite instability. After adjustment for TNM stage, tumor differentiation, adjuvant chemotherapy, and lymphovascular invasion, the loss of SMAD4 was found to be an independent prognostic factor for worse 5-year progression-free survival (hazard ratio [HR], 1.27; 95% confidence interval [CI], 1.01 to 1.60; p=.042) and 7-year cancer-specific survival (HR, 1.45; 95% CI, 1.06 to 1.99; p=.022).

Conclusions

We confirmed the value of determining the loss of SMAD4 immunohistochemically as an independent prognostic factor for CRC in general. In addition, we identified some histologic and molecular features that might be clues to elucidate the role of SMAD4 in colorectal tumorigenesis and progression.

Prognostic role of Tif1γ expression and circulating tumor cells in patients with breast cancer

Transcription intermediary factor 1γ (Tif1γ), a ubiquitous nuclear protein, is a regulator of transforming growth factor-β (TGF-β)/Smad signaling. Tif1γ can function as an oncogene and as a tumor suppressor. In the present study, Tif1γ levels were measured in the plasma of patients with breast cancer in order to investigate the association of Tif1γ with overall survival (OS). The results indicated that Tif1γ is an independent prognostic and predictive factor in breast cancer, and thus, a promising target protein for use in diagnostics and patient follow-up. Plasma levels of Tif1γ were measured in samples obtained from 110 patients with operable breast cancer and in 110 healthy volunteers at the Breast Cancer Department of Yangpu Hospital between 2008 and 2016. The association between Tif1γ levels and clinicopathologic parameters, and the OS in a follow-up period of 98 months was evaluated. The prognostic significance was assessed using the Kaplan-Meier method. The levels of Tif1γ were significantly lower in patients with breast cancer compared with healthy controls. The average concentration of 18.40 ng/ml was used to discriminate between Tif1γ-positive (52) and Tif1γ-negative patients (58). Tif1γ-positive patients had a significantly improved OS compared with Tif1γ-negative patients. In the multivariate analysis, Tif1γ was an independent predictor of a favorable OS in a prospective follow-up setting; thus, Tif1γ plasma levels are an independent prognostic factor for patients with breast cancer. These findings support the potential of using measurements of Tif1γ plasma levels to guide breast cancer therapy and monitoring. Further studies are required to validate Tif1γ as an easily detectable, non-invasive prognostic biomarker for breast cancer.

Anti-TIF1γ antibody predicted malignancy of thymic tumor with dermatomyositis as an "autoimmune tumor marker": A case report

RATIONALE

An association between inflammatory myopathy and malignancy has been recognized particularly in patients positive for anti-transcription intermediary factor 1γ (TIF1γ) antibody. We report a case of anti-TIF1γ antibody positive dermatomyositis (DM) associated with thymic carcinoma which radiographically mimicked benign tumor.

PATIENT CONCERNS

A 72-year-old man presented typical characteristic cutaneous manifestations and proximal muscle weakness with elevated levels of myogenic enzymes. An anterior mediastinal tumor was detected by computed tomography (CT) scan and radiographically assessed to be benign with distinct borders and little enhancement.

DIAGNOSES

DM with anti-TIF1γ antibody and thymic carcinoma.

INTERVENTIONS

Thymic carcinoma was completely resected by surgery. DM was induced into remission with glucocorticoid treatment.

OUTCOMES

The serum level of myogenic enzyme remained within normal range under low-dose glucocorticoid maintenance. No evidence of carcinoma recurrence with CT scan was observed at 1-year follow up.

LESSONS

The present case indicated that anti-TIF1γ antibody would play a role as the "autoimmune tumor marker" in patients with inflammatory myopathy.

Dermatomyositis and Immune-Mediated Necrotizing Myopathies: A Window on Autoimmunity and Cancer

Autoimmune myopathies (myositides) are strongly associated with malignancy. The link between myositis and cancer, originally noticed by Bohan and Peter in their classification in 1975 (1), has been evidenced by large population-based cohort studies and a recent meta-analysis. The numerous reports of cases in which the clinical course of myositis reflects that of cancer and the short delay between myositis and cancer onset support the notion that myositis may be an authentic paraneoplastic disorder. Thus, cancer-associated myositis raises the question of cancer as a cause rather than a consequence of autoimmunity. Among myositides, dermatomyositis and more recently, although to a lesser extent, immune-mediated necrotizing myopathies are the most documented forms associated with cancer. Interestingly, the current diagnostic approach for myositis is based on the identification of specific antibodies where each antibody determines specific clinical features and outcomes. Recent findings have shown that the autoantibodies anti-TIF1γ, anti-NXP2 and anti-HMGCR are associated with cancers in the course of myositis. Herein, we highlight the fact that the targets of these three autoantibodies involve cellular pathways that intervene in tumor promotion and we discuss the role of cancer mutations as autoimmunity triggers in adult myositis.

Identification of the SUMO E3 ligase PIAS1 as a potential survival biomarker in breast cancer

Metastasis is the ultimate cause of breast cancer related mortality. Epithelial-mesenchymal transition (EMT) is thought to play a crucial role in the metastatic potential of breast cancer. Growing evidence has implicated the SUMO E3 ligase PIAS1 in the regulation of EMT in mammary epithelial cells and breast cancer metastasis. However, the relevance of PIAS1 in human cancer and mechanisms by which PIAS1 might regulate breast cancer metastasis remain to be elucidated. Using tissue-microarray analysis (TMA), we report that the protein abundance and subcellular localization of PIAS1 correlate with disease specific overall survival of a cohort of breast cancer patients. In mechanistic studies, we find that PIAS1 acts via sumoylation of the transcriptional regulator SnoN to suppress invasive growth of MDA-MB-231 human breast cancer cell-derived organoids. Our studies thus identify the SUMO E3 ligase PIAS1 as a prognostic biomarker in breast cancer, and suggest a potential role for the PIAS1-SnoN sumoylation pathway in controlling breast cancer metastasis.

SnoN suppresses TGF-β-induced epithelial-mesenchymal transition and invasion of bladder cancer in a TIF1γ-dependent manner

The transcriptional regulator SnoN (also known as SKI-like proto-oncogene, SKIL), a member of the Ski family, has been reported to influence epithelial-mesenchymal transition (EMT) in response to TGF-β. In the present study, we investigated the role of SnoN in bladder cancer (BC). Differential expression of SnoN was not detected in BC tissues compared with that noted in adjacent non-cancerous tissues. SnoN was upregulated in response to TGF-β treatment, but had no effect on the TGF-β pathway, which may be explained by the low level of SnoN SUMOylation. TIF1γ, which catalyzes the SUMOylation of SnoN, was downregulated in BC tissues. Overexpression of TIF1γ restored the ability of SnoN to suppress the TGF-β pathway. Furthermore, TGF-β-induced EMT and invasion of BC cells were suppressed by TIF1γ in the presence of SnoN. Collectirely, our data suggest that SnoN suppresses TGF-β‑induced EMT and invasion of BC cells in a TIF1γ‑dependent manner and may serve as a novel therapeutic option for the treatment of BC.

TIF1γ interferes with TGFβ1/SMAD4 signaling to promote poor outcome in operable breast cancer patients

BACKGROUND

The Transforming growth factor β (TGFβ) signaling has a paradoxical role in cancer development and outcome. Besides, the prognostic significance of the TGFβ1, SMAD4 in breast cancer patients is an area of many contradictions. The transcriptional intermediary factor 1γ (TIF1γ) is thought to interact with the TGFβ/SMAD signaling through different mechanisms. Our study aims to define the prognostic significance of TGFβ1, SMAD4 and TIF1γ expression in breast cancer patients and to detect possible interactions among those markers that might affect the outcome.

METHODS

Immunohistochemistry was performed on tissue microarray (TMA) blocks prepared from samples of 248 operable breast cancer patients who presented at Centre Léon Bérard (CLB) between 1998 and 2001. The intensity and the percentage of stained tumor cells were integrated into a single score (0-6) and a cutoff was defined for high or low expression for each marker. Correlation was done between TGFβ1, SMAD4 and TIF1γ expression with the clinico-pathologic parameters using Pearson's chi-square test. Kaplan-Meier method was used to estimate distant metastasis free survival (DMFS), disease free survival (DFS) and overall survival (OS) and the difference between the groups was evaluated with log-rank test.

RESULTS

223 cases were assessable for TIF1γ, 204 for TGFβ1 and 173 for SMAD4. Median age at diagnosis was 55.8 years (range: 27 to 89 years). Tumors were larger than 20 mm in 49.2% and 45.2% had axillary lymph node (LN) metastasis (N1a to N3). 19.4% of the patients had SBR grade I tumors, 46.8% grade II tumors and 33.9% grade III tumors. ER was positive in 85.4%, PR in 75.5% and Her2-neu was over-expressed in 10% of the cases. Nuclear TIF1γ, cytoplasmic TGFβ1, nuclear and cytoplasmic SMAD4 stainings were high in 35.9%, 30.4%, 27.7% and 52.6% respectively. TIF1γ expression was associated with younger age (p=0.006), higher SBR grade (p<0.001), more ER negativity (p=0.035), and tumors larger than 2 cm (p=0.081), while TGFβ1 was not associated with any of the traditional prognostic factors. TGFβ1 expression in tumor cells was a marker of poor prognosis regarding DMFS (HR=2.28; 95% CI: 1.4 to 3.8; p=0.002), DFS (HR=2.00; 95% CI: 1.25 to 3.5; p=0.005) and OS (HR=1.89; 95 % CI: 1.04 to 3.43; p=0.037). TIF1γ expression carried a tendency towards poorer DMFS (p=0.091), DFS (p=0.143) and OS (p=0.091). In the multivariate analysis TGFβ1 remained an independent predictor of shorter DMFS, DFS and OS. Moreover, the prognostic significance of TGFβ1 was more obvious in the TIF1γ high patient subgroup than in the patients with TIF1γ low expression. The subgroup expressing both markers had the worst DMFS (HR=3.2; 95% CI: 1.7 to 5.9; p<0.0001), DFS (HR=3.02; 95 % CI: 1.6 to 5.6; p<0.0001) and OS (HR=2.7; 95 % CI: 1.4 to 5.4; p=0.005).

CONCLUSION

There is a crosstalk between the TIF1γ and the TGFβ1/SMAD4 signaling that deteriorates the outcome of operable breast cancer patients and when combined together they can serve as an effective prognostic tool for those patients.

Expression of the dermatomyositis autoantigen transcription intermediary factor 1γ in regenerating muscle

OBJECTIVE

Autoantibodies against transcription intermediary factor 1γ (TIF1γ) are found in many patients with dermatomyositis (DM). Although TIF1γ is known to play a role in the differentiation of other tissues, its functional role in muscle regeneration has not been elucidated. This study was undertaken to explore the regulation and functional role of this protein during muscle differentiation and regeneration.

METHODS

TIF1γ expression was analyzed in human muscle biopsy specimens using immunofluorescence microscopy. Immunofluorescence microscopy and immunoblotting analyses were used to study TIF1γ expression in a mouse model of muscle injury and repair. The effect of premature TIF1γ silencing on muscle differentiation was studied in cultured mouse myoblasts.

RESULTS

In muscle biopsy specimens from DM patients, TIF1γ was expressed at low levels in the nuclei of histologically normal muscle cells but at high levels in the centralized nuclei of atrophic, perifascicular myofibers expressing markers of regeneration. TIF1γ levels were also increased in regenerating myonuclei following muscle injury in mice. Premature silencing of TIF1γ in vitro using small interfering RNA did not accelerate the expression of myogenin, a transcription factor that plays a central role in regulating relatively early stages of muscle differentiation. However, premature silencing of TIF1γ did accelerate myotube fusion and the expression of myosin heavy chain (MyHC), a later marker of muscle differentiation.

CONCLUSION

The DM autoantigen TIF1γ is markedly up-regulated during muscle regeneration in human and mouse muscle cells. Premature silencing of this protein in cultured myoblasts accelerates MyHC expression and myoblast fusion. However, TIF1γ may function independently of, or downstream from, myogenin.

Reduced expression of transcriptional intermediary factor 1 gamma promotes metastasis and indicates poor prognosis of hepatocellular carcinoma

Transcriptional intermediary factor 1 gamma (TIF1γ) may play either a potential tumor-suppressor or -promoter role in cancer. Here we report on a critical role of TIF1γ in the progression of hepatocellular carcinoma (HCC). Reduced expression of TIF1γ was detected in HCC, especially in advanced HCC tissues, compared to adjacent noncancerous tissues. HCC patients with low TIF1γ expression had shorter overall survival times and higher recurrence rates than those with high TIF1γ expression. Reduced TIF1γ expression was an independent and significant risk factor for recurrence and survival after curative resection. In HCC cells, TIF1γ played a dual role: It promoted tumor growth in early-stage HCC, but not in advanced-stage HCC, whereas it inhibited invasion and metastasis in both early- and advanced-stage HCC. Mechanistically, we confirmed that TIF1γ inhibited transforming growth factor-β/ Drosophila mothers against decapentaplegic protein (TGF-β/Smad) signaling through monoubiquitination of Smad4 and suppressed the formation of Smad2/3/4 complex in HCC cells. TGF-β-inducing cytostasis and metastasis were both inhibited by TIF1γ in HCC. We further proved that TIF1γ suppressed cyotstasis-related TGF-β/Smad downstream c-myc down-regulation, as well as p21/cip1 and p15/ink4b up-regulation in early-stage HCC. Meanwhile, TGF-β inducible epithelial-mesenchymal transition and TGF-β/Smad downstream metastatic cascades, including phosphatase and tensin homolog deleted on chromosome ten down-regulation, chemokine (CXC motif) receptor 4 and matrix metalloproteinase 1 induction, and epidermal growth factor receptor- and protein kinase B-signaling transactivation, were inhibited by TIF1γ. In addition, we found that the down-regulation of TIF1γ in HCC was caused by hypermethylation of CpG islands in the TIF1γ promoter, and demonstrated that the combination of TIF1γ and phosphorylated Smad2 was a more powerful predictor of poor prognosis.

CONCLUSION

TIF1γ regulates tumor growth and metastasis through inhibition of TGF-β/Smad signaling and may serve as a novel prognostic biomarker in HCC.

Imbalanced expression of Tif1γ inhibits pancreatic ductal epithelial cell growth

Transcriptional intermediary factor 1 gamma (Tif1γ) (Ectodermin/PTC7/RFG7/TRIM33) is a transcriptional cofactor with an important role in the regulation of the TGFβ pathway. It has been suggested that it competes with Smad2/Smad3 for binding to Smad4, or alternatively that it may target Smad4 for degradation, although its role in carcinogenesis is unclear. In this study, we showed that Tif1γ interacts with Smad1/Smad4 complex in vivo, using both yeast two-hybrid and coimmunoprecipitation assays. We demonstrated that Tif1γ inhibits transcriptional activity of the Smad1/Smad4 complex through its PHD domain or bromo-domainin pancreatic cells by luciferase assay. Additionally, there is a dynamic inverse relationship between the levels of Tif1γ and Smad4 in benign and malignant pancreatic cell lines. Overexpression of Tif1γ resulted in decreased level of Smad4. Both overexpression and knockdown of Tif1γ resulted in growth inhibition in both benign and cancerous pancreatic cell lines, attributable to a G2-phase cell cycle arrest, but only knockdown of Tif1γ reduces tumor cell invasiveness in vitro. Our study demonstrated that imbalanced expression of Tif1γ results in inhibition of pancreatic ductal epithelial cell growth. In addition, knockdown of Tif1γ may inhibit tumor invasion. These data suggest that Tif1γ might serve as a potential therapeutic target for pancreatic cancer.

Tif1γ is essential for the terminal differentiation of mammary alveolar epithelial cells and for lactation through SMAD4 inhibition

Transforming growth factor β (TGFβ) is widely recognised as an important factor that regulates many steps of normal mammary gland (MG) development, including branching morphogenesis, functional differentiation and involution. Tif1γ has previously been reported to temporally and spatially control TGFβ signalling during early vertebrate development by exerting negative effects over SMAD4 availability. To evaluate the contribution of Tif1 γ to MG development, we developed a Cre/LoxP system to specifically invalidate the Tif1g gene in mammary epithelial cells in vivo. Tif1g-null mammary gland development appeared to be normal and no defects were observed during the lifespan of virgin mice. However, a lactation defect was observed in mammary glands of Tif1g-null mice. We demonstrate that Tif1 γ is essential for the terminal differentiation of alveolar epithelial cells at the end of pregnancy and to ensure lactation. Tif1 γ appears to play a crucial role in the crosstalk between TGFβ and prolactin pathways by negatively regulating both PRL receptor expression and STAT5 phosphorylation, thereby impairing the subsequent transactivation of PRL target genes. Using HC11 cells as a model, we demonstrate that the effects of Tif1g knockdown on lactation depend on both SMAD4 and TGFβ. Interestingly, we found that the Tif1γ expression pattern in mammary epithelial cells is almost symmetrically opposite to that described for TGFβ. We propose that Tif1γ contributes to the repression of TGFβ activity during late pregnancy and prevents lactation by inhibiting SMAD4.